Sigurd II

Sigurd Haraldsson (Old Norse: Sigurðr Haraldsson; 1133 – 10 June 1155), or Sigurd II, also called Sigurd Munn, was king of Norway from 1136 to 1155. He was son of Harald IV Gille, king of Norway and his mistress Thora Guttormsdotter (Þóra Guthormsdóttir). He served as co-ruler with his half-brothers, Inge Haraldsson and Eystein II Haraldsson. His epithet Munn means "the Mouth" in Old Norse. He was killed in the power-struggle against his brother, Inge, in an early stage of the civil war era in Norway.

Source: Wikipedia — https://en.wikipedia.org/wiki/Sigurd_II